Research of Process of Division of Grade Rolling on the Measured Blanks by Method of Breaking Bend at Static and Shock Loading

Abstract

Research of the process of cold breaking of rolling by bending under static and shock loads was conducted to determine the effect of loading speed on the power parameters of the separation process and the quality of the workpieces. Experimental researches are conducted for the three-point cold breaking by bending of templates from steel of different brands at the static and shock loading with the use of original equipment and rigging. Comparison of maximal force of breaking at the static and shock loading was estimated by the coefficient of dynamic, which for the different brands of steel laid down accordingly: ШХ15 - 0,7; 60С2 - 1,6; 45 - 2,0..2,2; 40Х - 1,8..2,1; 20 - 1,6..1,8 at speed of deformation to 18 m с. At the increase of speed of deformation the coefficient of dynamic grows for materials in the plastic and viscidly-resilient state and diminishes for materials in the fragile state. Than higher plasticity of material of templates, the greater size of coefficient of dynamic. Obviously, that for the exposure of inclination of materials of templates to fragile destruction it is necessary to apply the higher values of speed of loading. With the growth of speed of deformation geometrical exactness of blanks from the different brands of steels, gets better, but not significant. The most high quality was shown by blanks at the division of standards from fragile and viscoelastic steels: ШХ 15, steel of 60С2, steel 45, steel of 40Х. It is identified that greater part of energy of deformation is spent on an origin and viscid growing up of crack, while energy expended on fragile destruction is insignificant. Got results can be used for the improvement of the technologies of process of division of grade rolling on the measured blanks by the method of the cold breaking by a bend.

Study of the Process of Breaking Rolled Steel by Bending for Stamping Under Impact and Combined Loading

“…In the papers 8 , the well-known model of specimens' impact testing for concentrated bending with an elastic-plastic hinge was used. In the study of plastic flow in the separation plane at three-point bending, conclusions are drawn.…”

“…P. 107-114. 8 Karnaukh S. G., Karnaukh D. S. Research of the influence of deformation speed on energy and power adjectives of the process of three-point cold bend breaking and on alignment integrity of raw parts. Metallurgical and Mining Industry.…”

“…The papers 10 presents a complex mathematical model of the specimen static-dynamic loading according to the scheme of three-point bending on a press-hammer with the same direction of deforming forces. It differs from the known models by taking into account the preliminary static loading and design features of the press-hammer.…”